1. Field of the Invention
The present invention relates to a collapsible bulk container, which is used together with a so-called liner in the form of a bag shaped inner layer for the transport and storage of liquid, paste and particle goods.
2. Description of the Related Art
Collapsible containers of pallet container type are a popular type of containers due to the considerable reduction of the return transport volume. Collapsible containers are advantageously manufactured of thermoplastic material which gives light and yet sturdy containers with surfaces that are easy to keep clean. Thermoplastic containers do furthermore have the advantage that the tare weight doesn't change which is the case with for example wood containers where the tare weight might double if the wood becomes wet. Further advantages is that thermoplastics doesn't corrode, as everyone knows, which is the case with containers made of-metal such as aluminium and steel. Most thermoplastic materials does furthermore have a good resistance towards chemicals such as for example acids and alkali which not could be said to be the case with wood or metals.
Handling of bulk goods is separated from case goods by the fact that it can be poured, pumped or ladled while case goods most often is picked. Mineral water can serve as an example of the differences between the two types of goods. The mineral water could either be supplied in tanks for pumping and pouring which would be regarded as bulk handling, or in bottles or cans, which would be regarded as case handling. As further examples of substances that can be bulk handled can be mentioned, fluid substances with various viscosity, particles, powders, grain, granulate or paste-like substances. Such substances can be further exemplified as chemicals for industrial use, semifinished and finished products within the food industry, petrochemical products such as oil, fuels and coal as well as plastic granulate.
Sealing problems between the different parts of the collapsible container will inevitably occur when handling powder, smaller particles and fluids. These sealing problems are most easily overcome by using a so-called liner which is placed on the inside of the erected container. This liner is advantageously given the shape of a completely closed bag with the same shape as the inner volume of the container.
The liner is suitably provided with a filling socket at the upper side and an emptying socket at the lower side. The container must of course also be provided with a hole at the lower end making the emptying socket accessible. A further advantage with a liner, besides solving the sealing problems, are that it becomes easy to meet high hygienic demands.
When handling fluid and particle goods the liner will be exposed to forces, often hard to predict, especially at acceleration, retardation and bumps. These forces will cause abrasion on the liner which can cause the liner to rupture so that the content will leak. This will of course cause some inconveniences but can also be hazardous if the container is used for transporting dangerous goods.